1)If that's the case, why not reference DS9 and VOy, too? They aren't what the general populace think of when they hear Star Trek, but they too have their fans nonetheless.This is actually something I liked about the episode. The final episode of Enterprise was, well, greater than just the final episode of Enterprise - it was the conclusion to a whole era of Star Trek. What we now and then called the Berman era, because Rick was there was a producer from TNG's first season all the way to ENT's final year.Making the finale somekind of "baton passing back to TNG" exercise pretty much ruined it for me. Having Arik Soong (who was at least a boné fide and unusual ENT character) was about as much of a nod as fans needed in that direction frankly. I'm sure if you'd worked within the Trek factory back in 2005, TNG were definitely the glory days of high ratings and massive media interest.
It made sense, then, for the episode to reference to popular highlight of those years, which was TNG - good or bad, all the series that followed were merely riding the dwindling tidal wave and goodwill spurred by TNG's popularity until there was, in the end, nothing left.
2)There's a slight throw-back, and there's taking over the whole damn ending. The references to "All good things" and "The next generation!" were just flat-out insulting, IMO. The writers meant well, no doubt, but did they ever consider the possibility that not every Trek fan loved TNG (Yes, really) and that not every ENT fan was familiar with TNG and wanted a finale that was about the show they did know?
Fact is, heavy mainstream interest had long since died well before the finale. Some would argue it died even before Enterprise's creation. And frankly, both B&B and Paramount's chase to capture the glory days of TNG led ET and VOY before it in a downward spiral.
If we needed that much screen time dedicated to any other Trek show in a finale episode, it should have been TOS, hands down.